I would say that it has some truth to it, but I would like to add something to it. From my experience, you do tend to lose some trades but that doesn't mean you would not win on the next ones. You should not indeed regret any trades but when you do receive a loss or profit, you should learn from that trade and repeat the strategies that worked and never repeat that ones that didn't. This is something hard to comprehend, since not all strategy that worked before will work again, nor will a strategy that did not work will not work in the next time you do it. Experience is something very important in gambling, so take every trade as a learning experience.